From German Patent Disclosure DE 101 08 547 A1, an apparatus and a method for controlling surgical instruments in a surgical operation is known. The surgical instrument is guided by a robot or manipulator. The area of a patient, such as a knee, in which a surgical operation is performed with the surgical instrument is imaged during the operation by an X-ray system. In the X-ray image, a view of the surgical instrument is incorporated in a correct position. A position-detecting device detects both the position of the X-ray system and the position of the robot. The position of the area of the patient in which the operation is performed is also detected. In order to establish a relationship between the spatial position of the surgical instrument and the spatial position of the area in which the operation is to be performed, the relation between the working area, such as the tip, of the surgical instrument and the positioning of the robot is known. The position of the working area of the surgical instrument is thus not detected directly.
From EP 0 220 501 B1, an X-ray diagnostic system with system components that are adjustable by a control device is known. An X-ray tube, a picture-taking system, and a patient bed are provided as the components of the system, each individually adjustable in three dimensions. Each of the system components can be suspended from adjusting mechanisms in the manner of robot arms. As a safety device, a television camera aimed at the freely spatially movable system components may be provided, which is connected to a computer in such a way that the positions in which objects or persons recognized by the television camera are located are blocked. Moving equipment or parts may also be equipped with optical, tactile or ultrasound sensors. Such sensors on movably supported equipment or parts recognize an approach to an object or a person but do not serve as an absolute measurement system.
In US Patent Application 2004/0106916 A1, a computer-controlled guidance system and a method for surgical procedures are described. A surgical instrument is moved, with the aid of a haptic device that is triggered by commands of a surgeon, toward a target area on a patient. In a computer-assisted surgery system (CAS), virtual haptic objects are determined that guide and/or restrict movements and a working procedure of the surgical instrument.
In general, when robots are used in human surroundings, stringent safety demands need to be met. As a rule, the working area of the robot may not be accessible by the persons using or controlling the robot. Typical examples of safety devices are photoelectric beams which shut off or stop the robot as soon as a human or an object comes relatively close to the robot's working area. However, the photoelectric beam does not affect courses of motion of the robot, as long as the human or the object is permissibly located outside the working area or range of the robot. Thus, the photoelectric beam intervenes in the operation of the robot only in an extreme case, but does not contribute to improving or increasing the safety of the courses of motion of the robot during intended operations.